QT Creator configuration change to solve linking error?

Question

Building a QT application, I have a linking error of the following form

mainwindow.obj : error LNK2019: unresolved external symbol "public: __cdecl GLWidget::GLWidget(class QWidget *)" (??0GLWidget@@QEAA@PEAVQWidget@@@Z) referenced in function "public: __cdecl MainWindow::MainWindow(class QWidget *)" (??0MainWindow@@QEAA@PEAVQWidget@@@Z)

Where GLWidget is a custom class derived from QGLWidget

My theory is that the problem is caused by a an old version of the class and that cleaning the code would solve the problem.

15:50:59: Running steps for project qtTest1...
15:50:59: Starting: "C:\Qt\qtcreator-2.6.2\bin\jom.exe" clean
--- lots of lines
15:50:59: The process "C:\Qt\qtcreator-2.6.2\bin\jom.exe" exited normally.
15:50:59: Configuration unchanged, skipping qmake step.
15:50:59: Starting: "C:\Qt\qtcreator-2.6.2\bin\jom.exe" 
C:\Qt\Qtbuild\qtbase\bin\uic.exe ..\qtTest1\mainwindow.ui -o ui_mainwindow.h

Unfortunately, I can't seem to clean the code doesn't seem to work and I wondering if my error would be solved if I forced QT to reconfigure itself so that the following line would not occur

Configuration unchanged, skipping qmake step.

Answer 1

The solution was to run qmake command from the Qt Creator menu.